ghc-mod is a backend program to enrich Haskell programming in editors. It
strives to offer most of the features one has come to expect from modern IDEs
in any editor.
ghc-mod provides a library for other haskell programs to use as well as a
standalone program for easy editor integration. All of the fundamental
functionality of the frontend program can be accessed through the library
however many implementation details are hidden and if you want to
significantly extend ghc-mod you should submit these changes upstream instead
of implementing them on top of the library.
For more information, please see its home page.